Hydrogen Production and COD Elimination Rate in a Continuous Microbial Electrolysis Cell:The Influence of Hydraulic Retention Time and Applied Voltage

摘要

The influence of the applied voltage (V_(app)) and the hydraulic retention time (HRT) on hydrogen and methane production and the removal rate for chemical oxygen demand (COD) was studied in a membrane-less microbial electrolysis cell with a Ni-based cathode. When a synthetic effluent from a dark-fermentation process was fed continuously into the anodic chamber, an increase in both the V_(app) (from 0.6 to 1.0 V) and HRT (from 8 to 12 h) increased the hydrogen production rate from 0.18 to 1.42 L A~-1 d~-1 (liters per liter of anode per day) and the COD elimination rate from 46 to 94%. The influences of V_(app) and HRT on hydrogen production and the COD removal rate were found to be interdependent. Whereas acetic and butyric acids were easily degraded, propi-onic acid exhibited pseudo-recalcitrant behavior.